1. Field of the Invention
This invention relates to a suspension rolling tester for measuring the movement of suspensions of a vehicle when the vehicle is rolled.
2. Prior Art
In a vehicle such as an automobile, when it travels to the right or left, namely, when it corners, there occurs rolling in the vehicle which is different from a direct traveling thereof.
If such rolling occurs, a ratio of load movement of the right and left wheels is largely differentiated between the front and rear wheels owing to the difference of a spring constant in the suspensions of the coil springs of the front and rear wheels of the vehicle. The load movement ratio exerts an influence upon steering characteristics (under steering or over steering of the vehicle). When the rolling occurs, an alignment characteristic of the wheels is also changed to vary the steeling characteristic.
Accordingly, the movement of the suspensions when the rolling occurs, namely, the load movement amount and the alignment variation amount between the inner and outer wheels, i.e. the right and left wheels are respectively measured and these amounts are required to be always kept in a good condition (normal state) so as to permit the vehicle to travel safely.
There have been proposed various testers as measuring devices for measuring the movement of the suspensions.
In the case of a conventional measuring device for measuring suspension characteristic, the vehicle to be measured is carried in or conveyed to a garage, then it is generally fixed by a fixing means, and a vertical movement is applied to the right and left wheels of the fixed vehicle by a roll input device composed of a driving means such as a hydraulic cylinder which is installed in a pit formed by digging the earth to substantially a deep length, thereby rolling the suspensions of the wheels, so as to realize a condition as if the vehicle were actually rolled. The movement of the suspensions has been thus detected based on the result of measurement.